Modular hull vessel and method of operation

ABSTRACT

A waterborne vessel having a personnel and/or cargo carrier surface hull module, which normally seats on the surface of the water when at rest, is connected by depending struts to a submerged displacement hull module which contains the vessel engines, and its propulsion and steering means, and which provides a substantial portion of the buoyancy for the entire vessel. The struts are designed for extension and retraction so that the displacement hull module may be raised or lowered. The displacement hull module is constituted as a hydrodynamic lift body which, when in lowered position while the vessel is underway, lifts and maintains the entire personnel hull module out of the water to a height at which its bottom is out of contact with the surface of the water and above the crests of any waves thereon. When the vessel is docked or operating in shoal water the displacement hull module is positioned in substantial mating engagement with the bottom of the personnel hull module.

United States Patent [72] lnventor Gabriel V. De Lizasoain Rockville,Md. [21] Appl. No. 712,846 [22] Filed Mar. 13, 1968 [45] Patented July6, 1971 [73] Assignee Tecnlco, Inc.

Washington, D.C.

[54} MODULAR HULL VESSEL AND METHOD OF OPERATION 5 Claims, 2 DrawingFigs.

[52] U.S.Cl 114/77, 114/16, 114/665 [51] Int. Cl B63b 3/02, B63b 1/18[50] Field ofSeaI-ch ..114/0.5,0.5 D, 77, 61, 665, 16

[56] References Cited UNITED STATES PATENTS 3,279,407 10/1966 Stenger 114/665 Primary Examiner-Trygve M. Blix Atlorney-Townshend & MeseroleABSTRACT: A waterborne vessel having a personnel and/or cargo carriersurface hull module, which normally seats on the surface of the waterwhen at rest, is connected by depending struts to a submergeddisplacement hull module which contains the vessel engines, and itspropulsion and steering means, and which provides a substantial portionof the buoyancy for the entire vessel. The struts are designed forextension and retraction so that the displacement hull module may beraised or lowered. The displacement hull module is constituted as ahydrodynamic lift body which, when in lowered position while the vesselis underway, lifts and maintains the entire personnel hull module out ofthe water to a height at which its bottom is out of contact with thesurface of the water and above the crests of any waves thereon. When thevessel is docked or operating in shoal water the displacement hullmodule is positioned in substantial mating engagement with the bottom ofthe personnel hull module.

PATENTED JUL 6 I9?! FIG. I

WATER LINE FIG. 2

INVENTOR GABRIEL V. de LIZASOAIN A'rmmxws MODULAR HULL VESSEL AND METHODOF OPERATION BACKGROUND The present invention relates to the field ofsurface waterborne vessels which displace a weight of water equal totheir own weight. In such vessels the portion of the hull above thewaterline is commonly called the surface hull and the portion beneaththe waterline is referred to as the displacement hull. The cruisingspeed of such vessels is adversely affected by the hampering effect ofwater resistance, surface drag, and particularly the resistance ofwaves. Wave impact force acts not only against the exposed surface hullbut also against a portion of the submerged displacement hull.

Marine architecture has developed surface waterborne vessels equippedwith hydrodynamic lift means operative when a vessel is underway to liftand hold the entire hull out of contact with the water surface and at aheight sufficient to clear the crests of waves. U.S. Pat. No. 2,906,228is representative of such vessels; which have come to be known in theart as Hydrofoils." This is a generic term applied to any type ofwaterborne vessel in which struts depending from its hull carrysubmerged hydrofoil bodies whose angle of incidence may or may not beadjustable. When the vessel is underway, these submerged hydrofoilbodies operate hydrodynamically to lift the entire hull of the vesselout of the water and support it with its bottom out of contact with thewater surface and above the crests of waves thereon. This elevateddisposition of the hull enables operation of the vessel at speeds muchfaster than speeds attainable by conventional propulsion means while thevessel is seated on the surface of the water. Ordinarily, the submergedhydrofoil bodies carry propulsion means and steering means for operatingthe vessel, which means are connected through the struts with enginesand controls in the elevated hull. Although the present invention ispertinent to the foregoing general field of marine architecturedevelopment, it is founded upon a different and novel application of thebasic principles which heretofore have governed the prior artdevelopment of waterborne vessels designed so that, when underway,vessel contact with the water through which it is moving is minimized tothe greatest possible extent.

in the hydrofoil" type of vessel illustrated in the aforesaid U.S. Pat.No. 2,906,228 such contact is minimized by lifting the normaldisplacement hull of the vessel entirely out of the water after thevessel is underway. In another prior art type of vessel designed tominimize such contact, represented by German Pat. No. 590,270, asubmerged displacement hull portion of the vessel is connected byupstanding struts to a personnel carrier hull which is held above andout of contact with the water surface solely by buoyancy impartedthrough displacement action of the submerged hull portion, which portionis streamlined to offer the least possible resistance to its passagethrough the water.

At the present stage of marine architecture development, the hydrofoilprinciple introduced by Alexander Graham Bell is the basis of prior artmethods and means employed to lift the hull ofa vessel entirely out ofthe water and hold it clear above the surface while the vessel isunderway. In all such methods and means known to me prior to the adventof my present invention, hydrofoil bodies are separately and/orindependently attached to some portion of the vessel's hull, andgenerally are subject to independent control to vary their angles ofincidence whereby to regulate their hydrodynamic lift action while thevessel is underway.

At this point attention is directed to the fact that a mere streamlinedbody moving in the direction of its longitudinal axis in a horizontalplane through a body of water is, while so moving, per sehydrodynamically incapable of exerting a vertical lifting force.

Although modern adaptations of the hydrofoil to normally surfacewaterborne vessels have accomplished the objective of lifting a vesselout of the water and supporting it with its bottorn out of contact withthe water surface and clear above the tops of waves while the vessel isunderway, the advantages thus gained are greatly ofiset in practice bythe complexity of the problem of balancing a large mass on a supportwhich is only a small fraction of the weight of the mass; therebycreating an essentially unstable dynamic system. In such vessels thehull, normally designed for water displacement use, is lifted out of thewater and actually flown through the air while supported by foilsnormally designed for air use but which move through water instead.Furthermore, the lift requirements are such that the horsepower presentused in these vessels could practically drive a conventional planinghull vessel through the water at approximately the same speed.

SUMMARY The present invention provides a novel method and means forcontrolling the in transit attitude of a surface waterborne vesselwhereby to minimize Water resistance, and particularly the resistanceimparted by the action of waves. In marine architecture, wave resistancein relation to the speed of a vessel is expressed in Froude numbers,which increase with increase in speed. It is known that at Froudenumbers of 0.3 and greater, wave resistance increases at a very fastrate; so much so that the speed of full bodied conventional surfacevessels (vessels with Archimedes principle displacement hulls) islimited to a Froude number of about 0.5.

The present invention provides also a normally surface waterborne vesselthat supports its weight by means of a submerged displacement hull, inwhich the displacement hull itself is distinct from the surface hullportion of the vessel and is constituted as a hydradynamic lift body,operative when the vessel is underway, to lift the entire surfaceportion of the vessel from the water and support it at a selected heightabove its surface while the entire displacement hull remains submerged.

The present invention additionally provides a surface waterborne vesselhaving a surface hull and a separate submerged displacement hullconnected thereto and which displaces a weight of water equal to asubstantial portion of the entire weight of the vessel, in which thedisplacement hull is vertically movable bodily below the surface hull,and in which the displacement hull is constituted as a hydrodynamic liftbody operative, while the vessel is underway, to lift the entire surfacehull to a selected height above the surface of the water and support itat that height while the displacement hull remains submerged.

The present invention makes it possible to utilize nuclear power for theoperation of large merchant vessels, passenger liners, naval craft andthe like, in a more economical and practical manner than with currentinstallations using atomic reactors which require massive shielding.

In its broad aspects, as here shown, the surface waterborne vessel ofthe present invention comprises a surface hull module and a separate,submerged, displacement hull module. Both are watertight. When assembledin mating relation, as seen in FIG. l, they constitute in their entiretya complete surface waterborne vessel in which the surface hull module isdesigned as the general utility and personnel carrier portion, and inwhich the displacement hull module carries the power plant, thepropulsion means, fuel, and other mechanism necessary to operate thevessel. The displacement hull module constitutes in its entirety ahydrodynamic lift body and, in addition, provides a substantial portionof the buoyancy for the entire vessel.

The two modules are connected by the struts arranged to permit relativevertical movement between the modules such that the displacement hullmodule may be raised and lowered in relation to the surface hull module.The displacement hull module is provided with buoyancy regulating meansand also with hydrodynamic lift action regulating means, both controlledfrom the surface hull module.

When the vessel is docked, or operating in shoal water, the hull modulesare maintained in substantially mated engagement and with the surfacehull module seated on the water surface in the conventional manner ofwaterborne vessels. When the vessel is in deep water, and it is desiredto cruise with the bottom of the surface hull module elevated above andout of contact with the water surface and wave crests, the submergeddisplacement hull module is lowered to its limit depth. At this stagethe surface hull module remains seated on the water surface and providesa minor portion of the vessel's buoyancy. When the vessel is put inmotion with the displacement hull module in lowered position, theresulting hydrodynamic action of the displacement hull module resultingfrom its forward motion through the water applies a vertical lift forcewhich, in conjunction with the buoyancy lift force of the module,operates to lift the surface hull module entirely out of the water andto hold it supported in raised position with the bottom of the surfacemodule out of contact with the water surface and spaced above the crestsof waves while the vessel is underway.

Buoyancy of the displacement hull module and also its generatedadditional hydrodynamic lift action are regulated by controls in thesurface hull module operating through the struts that connect themodules. Furthermore, the displacement hull module may be equipped withconventional hydroplanes (not shown) similar to those employed onsubmarines for directional inclination of the hull as it moves throughthe water, and which are operated by controls in the surface hullmodule.

IN THE DRAWINGS FIG. 1 is a schematic representation in side elevationof a modular hull vessel incorporating the present invention, prior todeployment of its displacement hull module.

FIG. 2 is a schematic representation of the vessel shown in FIG. 1, butwith its displacement hull module in fully deployed position, with thevessel underway.

DETAILED DESCRIPTION The foregoing drawings are schematicallyillustrative of the best method and means I have thus far devised forreducing my invention to practice.

As shown, a surface waterborne vessel, indicated in its entirety byreference character 10, has a surface hull module 11, and a submergedArchimedes principle displacement hull module 12 which displaces aweight of water equal to a sub stantial portion of the entire weight ofthe complete vessel. The surface module is the normal personnel carrierportion of the vessel, having the usual accomodations for crew, cargo,and passengers if any. The displacement hull module contains theengines, and the propulsion and steering mechanism for operating thevessel and may include cargo holds. It contains also the fuel supply andother mechanism for operating the vessel. Struts l3, operative forvertical extension and retraction, permanently connect the modules sothat the displacement hull module may be raised and lowered relative tothe surface module. The struts 13 may provide communication between themodules and may be designed to permit the free passage of personnel fromone to the other and to contain means for conveying engine exhaustproducts of combustion from the displacement hull as well as forventilating it.

The bottom 14 of the surface hull module is watertight and preferably isdesigned for substantial mating engagement with the top of thedisplacement hull module when the latter is in fully raised position.The displacement hull module is itself watertight; so that the modulesare capable of movement through the water as independent waterbornevessels connected as a unit by the struts l3 and any other means thatmay be desired. As indicated in phantom, the displacement hull module isequipped with conventional ballast tanks 15 for regulating its buoyancyin the conventional manner of such devices.

The paramount feature of the present invention is the use of thedisplacement hull module itself to impart a hydrodynamic lift forcesufficient, when the vessel is underway, to lift the entire surface hullmodule from the water and support it in elevated position as shown inFIG. 2. For this purpose the displacement hull 12 is constituted as ahydrodynamic lift body which acts in accordance with the laws ofhydrodynamics to lift the entire vessel as it moves through the water.At the same time, it provides a substantial portion of the buoyancy forthe entire vessel.

The lift action of the displacement hull module is under selectivecontrol by regulator means 16, here shown as conventional spoilers onits top surface, operative to vary selectively the hydrodynamic effectof the hull.

The modular hull arrangement of the present invention is particularlyuseful in its adaptation to the employment of atomic power for theoperation of surface waterborne vessels. A nuclear reactor carried inthe displacement hull module is effectively shielded from the surfacehull module is effectively shielded from the surface hull by the in situlayer of water above the top of the displacement hull when it is inlowered position. The insulating effect of water on radioactiveemissions is well known, but so far as I am aware the prior art has notmade use of sea water in situ for shielding a nuclear reactor that isthe power source for operation of a surface waterborne vessel. In thisrespect my invention is unique.

From the foregoing, it is apparent that the present invention isfundamentally a normally surface waterborne vessel that supports itsweight by means of a submerged hydrofoil which actually is also a waterdisplacement hull of the vessel and which provides a substantial portionof its buoyancy. The displacement hull operates hydrodynamically whilethe vessel is underway to exert a vertical force tending to lift thesubmerged hull to the surface of the water.

As used in the foregoing specification and in the following claims theterm displacement hull" means a hull which utilizes the Archimedesprinciple; and the term hydrodynamic lift body means a submerged bodywhich, when moving through water, acts in the manner of an airfoilmoving through air.

METHOD OF OPERATION For docking and for relatively shoal water cruisingthe modules 111 and 12 are connected substantially in mating engagementas shown in FIG. 1. At this stage the attitude of the complete vessel issuch that the modules together constitute an overall Archimedesprinciple hull assembly which in its entirety displaces a weight ofwater equal to the weight of the vessel. The displacement moduleprovides a substantial portion of the vessel's buoyancy and theremainder is supplied by the surface module.

When the depth of water is sufficient for cruising with the submergeddisplacement hull lowered, appropriate mechanism controlled from thesurface hull is operated to lower the displacement hull module to itslimit depth, and the ballast tanks are manipulated to decrease itsbuoyancy by lowering the center of gravity, thereby maintaining thevessel as a stable dynamic system. As the vessel proceeds, thehydrodynamic action of the fully submerged displacement hull moduleresulting from its forward motion through the water automaticallygenerates and applies a vertically acting force tending to lift themodule to the surface of the water. This added hydrodynamic lift,coupled with the constant lift exerted by the buoyancy of the submergedmodule, is sufficient to lift the entire vessel. Accordingly, when thesubmerged module 12 rises toward the surface it correspondingly liftsthe entire surface module 11 out of the water to the same extent.

So long as the vessel is in forward motion the generated hydrodynamiclift of the submerged module 12 is exerted continuously, and if notcontrolled it would automatically carry the module to the surface,thereby altering the attitude of the vessel. The entire surface modulewould then be held in elevated position at a height above the surface ofthe water equal to the length of the fully extended struts 13, thuscould cause the vessel to capsize.

Dynamic stability of the system is maintained in the present inventionby operation of the lift regulating means 16 to govern the extent ofgenerated hydrodynamic lift applied by the submerged module; so that themodule is not allowed to rise to a level of instability.

It will be apparent to persons skilled in the art of surface waterbornevessel design that, in an Archimedes principle hull, initial buoyancy ofdisplacement alone cannot supply the force required to lift a separatebut necessary component of the vessel to an abnormal height above thelevel of its loaded waterline while the vessel is underway. Additionallift force is necessary to accomplish that purpose, and it must beapplied in such manner that it does not render the dynamic system of thevessel unstable. In the present invention that additional lift force issupplied by the generated hydrodynamic action of a submerged hull thatcarries all the engines, fuel, propulsion means, steering means, andother mechanism required to operate the vessel, and which is constitutedas a hydrodynamic lift body.

it is within the purview of my invention, and intended, that the surfacehull module may be designed to provide either optimum aerodynamiccharacteristics for passage through air or a combination of aerodynamicand other designs so as to maximize its efficiency and utility as acarrier, whereby to maximize aerodynamic and hydrodynamic factors ineach of both media.

The portion of total buoyancy of the vessel that is provided by thesubsurface hull module is selectively variable for adaptation to localcruising conditions. Preferably it should be from about 40 percent toabout 95 percent.

From an alternate point of view, the present invention is a normallysurface waterborne vessel 11 complete in all respects except for itsengines, fuel tanks, propulsion and steering means, and auxiliarymechanisms, all of which are contained within a hydrodynamic lift body12 that is also a buoyance component which supports the vessel when itis at rest on the surface of the water. When the vessel is underway, thecomponent 12 may be lowered beneath the vessel; whereupon it functionshydrodynamically to generate and apply a vertical lift force which actsin addition to the vertical lift force of the components buoyancy toraise the component from its lowered depth toward the water surface andcorrespondingly lift the vessel ll completely out of the water by meansof the supports 13. The buoyance of the submerged component and also itsgenerated hydrodynamic lift effect are regulated selectively fromcontrols in the vessel to maintain it in elevated position at a heightsuch that the bottom of the vessel is out of contact with the water andabove the tops of any waves thereon. This necessitates a reduction inbuoyancy appropriate to maintain the dynamic system of the vessel in acondition of stability, but the loss is compensated by the addedhydrodynamic lift supplied by the component 12.

I claim:

1. The method of minimizing water and wave resistance against a surfacewaterborne vessel having a hull assembly including a personnel carriersurface module and an engine carrier subsurface module which togetherhave a combined buoyancy initially supporting the entire mass of thevessel, which method comprises: decreasing the initial buoyancy of thesubsurface module and lowering it below its initial depth; causing thelowered module to generate and exert a hydrodynamic lift force which,added to the remaining buoyancy lift of the lowered module, causes themodule to rise toward the surface of the water and correspondinglyelevate the surface module thereabove; and controlling the magnitude ofthe lift forces to maintain the subsurface module at a desired depthwhile the vessel is underway.

2. The method of minimizing water and wave resistance against a surfacewaterborne vessel having an Archimedes principle hull assembly includinga subsurface displacement module and a surface module sup orted thereon,which comprises: decreaslng buoyancy of t e subsurface module andlowering it below the surface module to an initial lower limit depthsubstantially greater in extent than its original depth; placing thevessel in forward motion; applying to the lowered subsurface module amotion generated hydrodynamic lift force sufficient when combined withthe instant buoyancy lift force of the module to lift the module to thesurface of the water while the vessel is in forward motion at cruisingspeed; and controlling magnitude of the combined hydrodynamic andbuoyancy lift force of the subsurface module so that it lifts andmaintains its supported surface module at a height above the watersurface substantially equal to the distance the subsurface module israised from its initial limit depth level.

3. The method of lifting and holding the hull of a normally surfacewaterborne vessel above and out of contact with the surface of the waterwhile underway, which comprises: lowering beneath the bottom of the hullan attached buoyancy component of the vessel containing the engines,fuel, steering and propulsion means, and other mechanisms for operatingthe vessel; decreasing buoyancy of the lowered component to maintain thedynamic system of the vessel in stable condition; manipulating thelowered component to create by motion of the vessel a hydrodynamic liftforce acting in addition to the remaining buoyancy lift force of thelowered component to raise the component and the attached hull to anextent such that the hull is held above and out of contact with thesurface of the water; and selectively adjusting the height at which thehull is held above the water surface by regulating the magnitude of thehydrodynamic and buoyancy lift forces of the lowered component.

4. In a surface waterborne vessel having an Archimedes principle hullconstituted by a subsurface module and a separate surface module mountedthereon, in which the subsurface module is a buoyant hydrodynamic liftbody providing a substantial portion of the buoyancy for the entirevessel; means for lowering the subsurface module to a limit depth belowthe surface module, said lowering means including means for supportingthe surface module of the subsurface module in vertically spacedrelation thereabove; means for selectively controlling the buoyancy ofthe subsurface module; and means for selectively controllinghydrodynamic lift action of the subsurface module whereby to apply tothat module a vessel-motion generated lift force which, added to thelift force of the buoyancy of the module, acts to raise the entirevessel to a level at which the means supporting the surface module holdsthe entire surface module out of contact with the water surface andabove the top of any waves thereon.

5. In a waterborne vessel having an above surface hull module and asubmerged buoyant displacement hull module: means operative while thevessel is underway to raise and lower the displacement hull module toselective positions of adjustment relative to the surface hull module;the body alone of said displacement hull module constituting meansoperative solely in response to forward motion of the vessel to generateand apply to the displacement hull module a vertical lift force inaddition to its inherent buoyancy lift force.

1. The method of minimizing water and wave resistance against a surfacewaterborne vessel having a hull assembly including a personnel carriersurface module and an engine carrier subsurface module which togetherhave a combined buoyancy initially supporting the entire mass of thevessel, which method comprises: decreasing the initial buoyancy of thesubsurface module and lowering it below its initial depth; causing thelowered module to generate and exert a hydrodynamic lift force which,added to the remaining buoyancy lift of the lowered module, causes themodule to rise toward the surface of the water and correspondinglyelevate the surface module thereabove; and controlling the magnitude ofthe lift forces to maintain the subsurface module at a desired depthwhile the vessel is underway.
 2. The method of minimizing water and waveresistance against a surface waterborne vessel having an Archimedesprinciple hull assembly including a subsurface displacement module and asurface module supported thereon, which comprises: decreasing buoyancyof the subsurface module and lowering it below the surface module to aninitial lower limit depth substantially greater in extent than itsoriginal depth; placing the vessel in forward motion; applying to thelowered subsurface module a motion generated hydrodynamic lift forcesufficient when combined with the instant buoyancy lift force of themodule to lift the module to the surface of the water while the vesselis in forward motion at cruising speed; and controlling magnitude of thecombined hydrodynamic and buoyancy lift force of the subsurface moduleso that it lifts and maintains its supported surface module at a heightabove the water surface substantially equal to the distance thesubsurface module is raised from its initial limit depth level.
 3. Themethod of lifting and holding the hull of a normally surface waterbornevessel above and out of contact with the surface of the water whileunderway, which comprises: lowering beneath the bottom of the hull anattached buoyancy component of the vessel containing the engines, fuel,steering and propulsion means, and other mechanisms for operating thevessel; decreasing buoyancy of the lowered component to maintain thedynamic system of the vessel in stable condition; manipulating thelowered component to create by motion of the vessel a hydrodynamic liftforce acting in addition to the remaining buoyancy lift force of thelowered component to raise the component and the attached hull to anextent such that the hull is held above and out of contact with thesurface of the water; and selectively adjusting the height at which thehull is held above the water surface by regulating the magnitude of thehydrodynamic and buoyancy lift forces of the lowered component.
 4. In asurface waterborne vessel having an Archimedes principle hullconstituted by a subsurface module and a separate surface module mountedthereon, in which the subsurface module is a buoyant hydrodynamic liftbody providing a substantial portion of the buoyancy for the entirevessel; means for lowering the subsurface module to a Limit depth belowthe surface module, said lowering means including means for supportingthe surface module of the subsurface module in vertically spacedrelation thereabove; means for selectively controlling the buoyancy ofthe subsurface module; and means for selectively controllinghydrodynamic lift action of the subsurface module whereby to apply tothat module a vessel-motion generated lift force which, added to thelift force of the buoyancy of the module, acts to raise the entirevessel to a level at which the means supporting the surface module holdsthe entire surface module out of contact with the water surface andabove the top of any waves thereon.
 5. In a waterborne vessel having anabove surface hull module and a submerged buoyant displacement hullmodule: means operative while the vessel is underway to raise and lowerthe displacement hull module to selective positions of adjustmentrelative to the surface hull module; the body alone of said displacementhull module constituting means operative solely in response to forwardmotion of the vessel to generate and apply to the displacement hullmodule a vertical lift force in addition to its inherent buoyancy liftforce.